Survey Issues

1. Survey Issues

2. Types of Bridge Survey • Standard Bridge Survey • Major Bridge Survey • Generally more extensive than std survey • May require specialized equipment such as boat and sounder • May require random survey data to create accurate DEM

3. Common Misunderstandings • Thalweg and stream bed only required in vicinity of bridge/culvert and any possible RPW • Roadway survey needs to extend beyond valley crest. This allows comparison of various cut/fill and bridge height scenarios • Accuracy can be critical to determining bridge parameters

4. Survey Issues • Geographic extent of data • Missing data • Density of data • Quality of data • Site conditions during field survey • Accuracy of data processing/coding • Accuracy of drawings • Timeliness of survey drawings

5. Check for errors Critically examine survey: • Look for consistency between different views • Compare with site visit notes and photos • Look for evidence of common errors • Assume that errors exist and then look for evidence to disprove your assumption

6. Examples